Review of Michael Gazzaniga’s “Who’s in Charge?” suggests that belief in free will fosters cooperation

Reason Magazine “In Search of Free Will and Moral Responsibility”

There’s some great commentary here, although I would certainly question whether “the worst type of free riding is criminal behavior, e.g., robbing, assaulting, and murdering others for personal gain”. One need only look to the ultimate defections perpetuated by the despots of the 20th Century to see that petty crime is hardly the worst form of selfish behavior. There is also a bit of a conflation here of not imposing the death penalty with “letting killers off the hook”.